iPhone App for internet UK Number?

[boxst]

I currently use Line 2 ( https://www.line2.com) to have a US phone number that rings on my iPhone with a dedicated App. I would like to do the reverse for an American colleague (i..e have a UK number preferably with UK/European minutes), can anyone recommend one? I can't find any that aren't just SIP numbers.

(I also have a VoIP/SIP UK number since moving house and the apps seem to be a bit flaky, so would prefer one that comes with a dedicated app for my colleague as Line2 works much better)

Thanks for any help.