If you plan to change your phone, you can easily move your karma and all your Jodels to the new device.
The first thing to do when you plan on changing your phone is to make sure that you back-up your present data. Make sure to create a back-up of your Jodel account as described here: https://jodel.zendesk.com/hc/en-us/articles/360018271833-How-do-I-save-my-Karma-Data-
Now, take the new phone and log in to your iCloud/Google account and then install Jodel. Upon opening the Jodel app, you should find all of your previous data.
If everything works fine, do not forget to do a factory reset of your old phone. This way you ensure that whoever gets hold of your old device will not be able to access your Jodel account.