Tip for #android users:
If you search for simple utility apps on #google's play store it will almost always give you a bunch of options that contain ads or ask for unnecessary permissions.
F-Droid is an alternative app store for android devices which exclusively lists apps published under the AGPL (a #copyleft / free-software / open-source license). It's possible to install F-Droid on a normal Android OS via its APK, but that can be intimidating.
Most of the apps on F-Droid are *also* available on the play store. So, even if you aren't ready to fully switch out of Google's ecosystem, you can still use F-Droid's search as a better way to find options that are (in my experience) free of ads and surveillance.
Each app features a page which links to their source code, which usually has a README file, which usually points to their page on the play store.
F-Droid - Free and Open Source Android App Repository
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.f-droid.org