Android UX Designer/Developer Full-time

We (Taler Systems SA/The GNU Project) are looking to hire software developers (volunteers also welcome) to write Free Software for F-Droid, specifically user interfaces for GNU Taler ( https://taler.net/ ).
– Oh, and before you worry: no blockchain, we’re not a crypto-currency).

We have flexibility with respect to to location (ideal would be Berlin, Luxembourg or Switzerland). Part-time/full-time employment or contract work are also generally possible, but full-time would be preferred.
Overall, we are looking for the following skills:

• MUST: F-droid application developer (Java/Kotlin, mostly UI). [Note: no Google Play, resulting app must work on F-Droid.]
• Bonus: Knowledge of networking stacks (NFC, REST) or cryptography would be helpful, but is really not required as the crypto is finished)
• Bonus: Cross-platform development ability for iOS would be a plus [Note: we will dual-license to be able to be listed in the App store, but recommend users to jail break and use GPL edition.]
• Bonus: UI/UX design experience

If you have any of these skills and want to work on privacy-enhancing Free Software, please contact me with a description of your skills, preferred type of employment (full time, part time, contract), current
location, and whether relocation is conceivable for you.