Afaik all smartphones browsers come with 'find' function.
Let me know which browser you use I'll help you use find function)
Forum software has never been smartphone-friendly in particular, or mobile-devices-friendly in general. It is good to have that function for lists of merit senders/donators to OPs, but it is still good enough to accept and keep using current version.
This function is more important and more meaningful when users look at threads with unsignificants received merits, and from limited merit senders. Because those threads are helpful, and have not yet received too many merits, so if readers have available sendable merits, they should spend some of their sendable merits to those OPs.
For huge merit-received OPs, it is good to send more merits to OPs, but it is still fine if readers don't send more to OPs.