[MBK]

It all depends on how and where you are roaming.

For limited roaming in some areas, Piranha is good. For Europe & US toggle counties Toggle is best, etc..

For the worldwide traveller, especially if you are using a dual sim phone, the Travelsims (airbaltic, onesimcard, Travelsims,...) are the best in my experience.

- if +372 is expensive to call airbaltic has free UK number, with 0.15 PER call.
- free incoming in 154 countries (even with 0 credit)
- free forwarding to 154 countries (even with 0 credit)
- most solid, stable, roaming I have seen
- no credit expiration for 2 years with airbaltic


And the advantage is that you will always be reachable on the same number as if in some countries another sim is preferable, you can forward your +372 for free to that other sim number. (best is dual sim anyway if you are serious about roaming).