6 open-source Android apps I’d use even if they weren’t free

Published Jul 18, 2026, 8:41 AM EDT Faisal Rasool has been a feature writer at How-to Geek since early 2024. He brings years of professional experience in simplifying technology for his readers on topics like mobile devices, PCs, and online privacy. He tries to help people get the most out of their gadgets and software with the least effort. In his teenage years, he spent hours every day tinkering with Android phones and Linux builds. Faisal started his career at WhatMobile in 2019 (mostly out of his obsession with Android) where he published over 2,000 news stories. Currently, he contributes to the news section over at AndroidHeadlines. He also authored more than 100 feature articles for SlashGear, covering Android, iOS, Web, Chromebooks, online privacy/security, and PC content. Faisal has a Bachelor's in English literature, and loves to read and write. He also loves watercolors, retro video games, animation, and cats. The beauty of Android is the huge ecosystem of awesome open-source apps available for the platform. There is an entire app store called F-Droid that exclusively features free and open-source apps. Some of these apps are so good that I would pay for them if they weren’t free. I’m sharing a few here. KDE Connect The ultimate desktop companion Credit: Lucas Gouveia/How-To Geek | chokchai suttinarakorn/Shutterstock If you’ve ever tried sending files or text back and forth between your Android phone and computer, you’ll know how annoying it can get. Most of the time, you end up emailing the file or sending yourself a text just to get the text across. The KDE Connect app was built to solve exactly this problem. KDE Connect is a cross-platform app, available on Windows, Linux, and Android, which lets you connect your phone and PC to do a bunch of useful things. I mostly use it to sync my phone’s clipboard and share files with the PC. However, KDE Connect also lets you control media playback, get phone notifications on the PC (even reply directly from the PC), and use your phone as a presentation remote or a trackpad. With KDE Connect, you can view the phone’s battery level without picking it up right from your desktop. If you can’t find the phone, you can ring it using the KDE Connect on the desktop and find it. Heliboard Your keyboard is online—use one that's offline instead Credit: Lucas Gouveia/How-To Geek I believe a virtual keyboard should always stay offline, but (sadly) there aren’t a lot of great options for Android. A lot of projects I’ve found are either abandoned or stuck in beta, but the one keyboard app you can wholeheartedly recommend to everyone is Heliboard. It replaced Gboard as my default, and I have no intention of going back. Heliboard never connects to the internet, so it’s much more privacy-friendly than any online keyboard. It supports multiple layouts and pretty much every language (you can enable multiple language packs simultaneously). There’s a clipboard history, where you can pin items as well. You can customize it to your liking with colors, styles, fonts, and scaling. Basically, you can create your own custom themes. It even lets you change the overlay text that appears on the spacebar, which I’ve never seen on any other keyboard app. Credit: HeliboardCredit: Heliboard Arguably, the best part is glide typing, which no other offline keyboard supports. Heliboard technically doesn’t have the feature built into it either because you have to download and import a Google library to make it work. The keyboard still stays offline, so I prefer it over Gboard. It’s a one-time setup and the typing experience is fantastic. Syncthing Escape your cloud storage subscriptions Credit: Lucas Gouveia/How-To Geek | Macrovector/Shutterstock If you want to ditch the cloud and find a better, more private way to back up your data, try Syncthing. If you have a spare laptop or PC lying around, you can turn it into a file server to stash your phone’s data. Alternatively, you can use your main PC for this. I use Syncthing to sync notes between my phone and PC, but you can use it for any file type—photos, videos, or documents. All you have to do is install Syncthing on the PC or laptop you’re using as the file storage server and create a shared folder. Then you install Syncthing on the phone, connect it with the PC, and the shared folder will now show up in the phone’s storage. Any file or folder you place in this shared space will be automatically uploaded to the PC. You’ll have to set up the folders such that the PC folder can only receive data and the phone’s shared folder can only send data; otherwise, wiping files from one space will sync those changes everywhere, and you’ll lose them. It’s easier than it sounds. The only downside is that the host computer needs to be online if you want to access the shared folder. That’s where a Raspberry Pi or a NAS will work best because they can be constantly online without sucking up a lot of power. I also recommend creating backups of the backups, so you don’t lose your data. In either case, it’ll save you the cost of cloud subscriptions, and you get to retain all your data. LocalSend Credit: Lucas Gouveia / How-To Geek | ZinetroN / Shutterstock LocalSend is the one app I have on every single device I own, and I encourage my friends and family to install it too. It’s a cross-platform app that makes sending and receiving files dead simple. Think of it as Apple’s Airdrop, except it works everywhere—Windows, Linux, macOS, iOS, Android, you name it. It’s easy to install and easy to use. You don’t need to connect to the internet to send files since LocalSend (as the name implies) shares files over the local network. Just launch the app, switch to the Receive or Send tab, and pick a device from the list of nearby devices, and you’re good to go. You can send entire folders, pieces of text, or single files. It also supports sharing via a link or sharing with multiple recipients at once. It’s fast enough, has no ads, and is very lightweight, so you can leave it running in the background. You can even set it to auto-start on boot. NetGuard Lock down your connection If you’re trying to save data, if you don’t want to block certain apps from accessing the internet, or if you want an easy way to lockdown traffic with specific filters, NetGuard is your friend. Android doesn’t natively support cutting off internet access for specific apps, but NetGuard gives you total control over that. First, you can see a detailed log of any app’s internet activity and let that guide how you filter your phone’s internet traffic. The filters are highly selective, so you can decide exactly which apps are on the blocklist and how they’re being filtered. For example, you can give Wi-Fi access to one app while restricting data access to another. You can even set it up to only allow the app to access mobile data or Wi-Fi while the screen is on, thus keeping the app from phoning home in the background. Plus, there’s a ‘Lockdown Traffic’ button that automatically disables access to all apps except the ones you’ve added to the allowlist. It’s a very handy utility for me and there aren’t many others like it. Termux A terminal from your phone Credit: Jordan Gloor / How-To Geek Termux is a terminal emulator for Android that lets you run useful commands, scripts, and TUI apps on your phone. It creates a sandbox within storage, so whatever you do within the terminal won’t affect your phone. You might be asking what you can even do with a terminal emulator on a phone, and the answer is: a lot. For starters, you can run text-based interface (TUI) tools like YT-DLP and download all kinds of media from the internet. You could grab webpages or upload and download files with Curl. Run media and document conversions with FFMPEG or Pandoc. You can SSH into other machines directly from your phone. Devs can use it to code on the go using Vim or Emacs and a physical keyboard. You can run Python or Bash scripts. Getting Linux distros (without GUI) working within Termux is trivial. People even run full fat Linux operating systems within Termux, including GUI desktop environments. It’s equal parts powerful and helpful because it’s like carrying a desktop terminal in your pocket. Android is an endless world of open-source apps (if you know where to look) The F-Droid store has plenty of other gems just like these six apps, and I encourage you to explore them yourself.