There's a fork called Fossify that is expected to replace the Simple Mobile Tools. There's a Gallery and File Manager app already. I am not sure how it's different from the pro version though. It's a fork of the Simple Gallary app that was in Fdroid.
F-Droid
F-Droid is an installable catalogue of FOSS (Free and Open Source Software) applications for the Android platform. The client makes it easy to browse, install, and keep track of updates on your device.
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And you can already get these forks through your fdroid client by adding the IzzyOnDroid repo! There's also the calendar that released!
This one is already available in the official f-droid repo: https://f-droid.org/en/packages/org.fossify.gallery/
Fossify is all about community-backed, open-source, and ad-free mobile apps. A fork of the @SimpleMobileTools, which is no longer maintained, and we're here to continue the legacy, bringing simple and private tech to everyone.
Here's a gallery app I switched to: https://github.com/IacobIonut01/Gallery Just know it's only for android 11 and higher. F-Droid link: https://www.f-droid.org/en/packages/com.dot.gallery/
I'll check this one out. Thanks!