But iOS offers no such option. If you tap a URL, it opens in Safari. If you tap a link to send an email, it opens in Mail. The default calendar is Apple’s Calendar app. And so on. You may not want to work that way and because Apple doesn’t give you any choice, you’re stuck with workarounds: using share sheets to open a web page in a different browser; copying an email link or address to create an email; and so on.
We’re at iOS 10, and Apple still hasn’t allowed users to make these choices. It seems ridiculous that, with a mature operating system, we’re still locked into Apple’s default apps. It’s not rocket science to make these changes; after all, there are protocols that funnel requests to specific handlers, the same way they do on the Mac. Let us choose the apps we want to use: It’s time to let iOS users have the same freedom of choice as Mac users.
He makes an interesting point about Apple not allowing users to change default apps like mail. Even if Apple can allow this won’t anytime soon. Why? simple most users don’t care about using default mail app. Most of them are not downloading third party email apps. Also I think it’s because of security reasons. The default apps are so integrated that it could ruin some of the iOS experience that Apple likes to control.