Just add their github repo url to Obtanium to install directly from source instead of using an app store.
https://github.com/MutinyWallet/mutiny-web
Discussion
And what is obtanium?
Let's you install apps directly from the source, circumventing app stores.
How?
Why are anything that is related to bitcoin so difficult to understand/use for average people?
It's a nascent space. The more mature parts (saving #Bitcoin using a hardware wallet) are more accessible today compared with parts under heavier iteration (noncustodial #Lightning experiments).
Because we’re early. It is like Internet in 1995. Devs need to implement more and more tools and layers. In the finality we will use Bitcoin without knowing we use it, like TCP/IP for example.
Obtainium has nothing to do with bitcoin.