I found 6 open source apps that are so good that I gladly pay for them

Closed software like Google’s Workspace suite is popular. But it has hidden layers I want visibility into, especially as awareness of tracking and data collection increases.

Likewise, open source software is becoming more appealing to people who want control over the tools they use. It isn’t limited to developers.

Core features are usually free. But many projects offer paid tiers for cloud or self-hosting tools, cross-device syncing, extra storage, and team perks.

I don’t mind paying for them because their value proposition matches how I use them. While I grab my credit card, here are six apps that made the cut.

Execute Linux commands with Termux

Become a Linux programmer on Android

I use Termux to download images and videos from web sources, among other unexpected uses. The app is a full Linux terminal, so you’ll need a basic understanding of the command line to begin.

I won’t call myself a developer, but I’ve spent a reasonable number of hours learning a few programming languages. I now have a few tricks up my coding sleeve.

For images, I grant Termux access to a folder. Then I pull the target file using the wget command followed by the image URL. For videos, I use yt-dlp or python -m yt_dlp and the link.

These commands cut out frustrating middle layers. Websites may have excessive ads, or download buttons may redirect me multiple times before giving me a file.

It’s mostly a straightforward process. But you might bump into a few setup steps and issues. A quick upgrade or reinstallation of the Termux packages with the pkg upgrade, update, or reinstall commands should fix them.

Be discreet with the lightweight Fossify Calendar

Track important events privately

Fossify Calendar is a lightweight and ad-free app. It’s part of its own ecosystem alongside other apps.

They can replace core tools like your gallery, contacts, messages, calculator, and file manager with offline alternatives. You’ll find them on the Google Play Store.

Calendar is my discreet companion for sensitive records, like period tracking or general routines I don’t want exposed. I may assign code names or specific colors to dates.

Then I export them in the iCalendar Specification (.ics) format and save them to my USB flash drive or transfer them to a new device.

The app is free and doesn’t require creating an account.

But if you want to support the developer, there’s an optional Thank You app that costs $3. It lets you apply customizations across other installed Fossify apps.

Keep your web browsing private with ProtonVPN

Hide from the world

Privacy advocates warn against free VPNs. They’re money grabbers, and they mostly fund themselves by injecting ads or selling your usage data.

Proton VPN is among the few exceptions, as it builds its model around paid tiers.

Independent security firms also audit its infrastructure annually. Proton passed the September 2025 no-logs check conducted by Securitum, a European cybersecurity firm known for securing banks and large organizations.

The free plan automatically selects the fastest available server, usually the closest or least congested option at that moment. If you’re not happy with the selection, switch servers.

Switching is randomized, and there’s a cooldown timer between each attempt. It gets longer the more you hop about. Even with those limits, the app is effective. I use it to bypass geo-blocking on streaming platforms and many websites.

Proton recently expanded connection controls on the paid plan, so now you can set country preferences. The app won’t default to the fastest server. Pricing starts at $10 monthly for the VPN Plus plan.

Get cross-device synchronization with KDE Connect

Bridge multiple devices

Interoperability between Android and Apple devices is awkward. KDE Connect makes it a breeze, and it’s completely free.

I installed the mobile and PC apps on my Realme 12+ and MacBook Air, and connected both devices to my Wi-Fi router. Then I approved the pairing to complete the setup.

I mostly use it to copy and paste text or links across devices. It also supports file sharing without cables or cloud uploads. Control media with the virtual remote or use your phone as a touchpad when you don’t feel like using your keyboard.

Create Markdown files in Joplin

Mark down important ideas

Markdown editors present an interesting way to write and format text. I started with Obsidian and loved its graph view. Seeing my ideas visually connected made everything feel alive.

I eventually switched to Joplin, which has a much lower learning curve. It lets you create notebooks and sub-notebooks without requiring an account or a vault.

But the base plan is affordable. It costs $4 a month for 10MB per note or attachment, 2GB of storage space, and unlimited device syncing, among other features.

Free cross-device syncing is available but requires linking to a personal cloud service like Dropbox or OneDrive.

Dropbox and OneDrive integration are other ways to spread files across devices. But they’re slower.

Connect all your email accounts to Thunderbird

Gather all your emails in one nest

I have three Gmail accounts and one Yahoo Mail account. I do fine managing them separately. But I prefer having everything in one place. It might be unsettling when you think about how one weak point can compromise all your accounts.

I trust Thunderbird to connect emails directly to my providers. Mozilla, the same company behind the Firefox browser, backs it. Mozilla has a long track record of building privacy-focused software for over 25 years.

Plus, it uses Open Authentication (OAuth) for sign-ins. I don’t type my password into the app, so it only receives a token instead of my actual credentials. I can always revoke access from my Google account.

Besides the consolidated emails, Thunderbird has an interface closely resembling Gmail. So, it didn’t take me time to adjust and manage my accounts.

I love that I can also choose how often emails sync and how many it loads at once.

Make the necessary small swaps

Not many apps meet my standards, especially when I’m trying to de-Google my devices and reduce reliance on cloud-heavy services. I’m glad I found this collection on the Play Store.

If you’re trying to move in the same direction, start small. Replace one app you use every day and use it for a while. Then notice what you gain and lose.

Start with low-risk apps like notes, calendar, or a browser substitute. If it works better than the original, replace it and move on to the next. Otherwise, keep trying.