Hello,
i'm a developer from Germany.
I know i propably shouldn't even try to get this job because of the last sentence of the project details, but please hear me out.
I'm obviously new on this platform and need some jobs to gather reviews.
I would use the Flutter framework, which uses one single codebase to deploy both required versions of your app.
That would even help you to keep the costs of e.g. maintenance down, because you only need to maintain one codebase.
For this simple app, i'm almost certain that i'm able to deliver today (CET)
Feel free to contact me to exchange further details or if you have further questions.
Best regards
Johan