Anyway To Block The Telegram Apps?

[adm1n0]

I can block the web app based on the domain but android and ios apps will still work 

[rotblitz]

What exact domain(s) did you enter to block it in the browser?  If it is the www subdomain like www.telegram.org, this is normally not used by apps, but other subdomains may be used.  Therefore you should enter telegram.org which blocks this and all of its subdomains.

If this does not help, visit your domain stats to possibly find related domains to be blocked.

[adm1n0]

I did indeed block telegram.org but apps still work

Looking at the stats didn't give me any clues 

[rotblitz]

Blocking with OpenDNS works only if DNS is involved.  I know from experience that many apps do not use DNS a lot, but IP addressing.  This does not require DNS.  I observed this on my router having a feature to identify and block accesses from directly entered IP addresses.

Therefore, to find out if DNS or IP addressing is being used by these apps, best would be to refer to the authors of these apps to hear more.  Here in this forum nobody can really know.  They should be able to tell you the domain names or IP addresses you had to block via OpenDNS or on the router.