@MBFTOM There is nothing stopping the onesignal plugin to work with iOS but there is no iOS WebView app to make use of it yet.
[nodebb-plugin-question-and-answer] Feature request
Link to GitHub
Now i've really wanted to use this plugin, although there is something theres missing which would really improve the plugin, it's also added on the "TODO" list but i haven't really found any progress on it lately.
Now I thought if it really would be hard to make a "Select as best answer" option for the person who created the thread, that would automaticly lock the thread and set it as "SOLVED"