Asking for payment is equivalent to stating "I have made something truly worth paying for". For example, it is groundbreaking or an incredibly useful addition to iOS. In most cases, consider not asking for payment and look towards open-sourcing your work. The 'soul' of making tweaks is to build something for the fun of it, not to run a business.
If you decide to release a paid tweak, it is not a matter of adding a price to your work and putting it on a default repository. You need to ensure the price is justified, and that the tweak matches customer expectations. After that, you also need to provide support and updates when necessary. To be clear: accepting payments means you become liable for handling a lot more than just writing code.
The following guidelines should be used to check that you are within customer expectations. Please note that individual repositories may also add their own expectations if you decide to release through them (e.g. [Packix](https:/