Developing an app is not easy or fast. Its time consuming and requires you pour a lot of your own time and money. We love your app and want to ensure it remains sustainable for you to continue development. Please make it as easy as possible for all of us to donate monthly by using the platforms a lot of us use. These being github sponsors, patreon, open collective, and liberapay.
For reference this is the voyager (formerly wefwef) developers github sponsors which is also a great project the community is starting to help fund https://github.com/sponsors/aeharding
And some servers have open collectives to pay their server bills which is also great https://opencollective.com/beehaw
Both/all options makes the most sense but an in app tip jar with recurring donations is really great.
I like the others as well because people can see transparently how much is being donated but yeah in app is definitely convenient too