If you are on holiday, you may still need the Internet. With Airalo you can book the appropriate eSIMs, which can be easily configured as a 2nd SIM, e.g. on the iPhone.
The process is simple: install the app, create an account, enter a payment method if necessary (in my case I chose a credit card) and then choose one of the desired eSIMs from the list.
Prepaid SIMs are offered by local providers. In Germany YES! Mobile is the partner who in turn uses the o² network. Offered are 1 GB for 7 days or 5 GB for 30 days - the prices themselves vary depending on the selected country and provider, but are in similar ranges between 3 - 5 US dollars for 1 GB for 7 days.
The setup itself is as simple as booking: once you buy a package, you get both a QR code and the settings for a manual configuration - which you need if you want to use the eSIM on the same device.
Once an eSIM has been set up, it can be recharged with credit when the volume is used up. This can also be done easily from within the app, so you don't have to do the basic setup several times.
If you want to know in advance whether the service is available for the selected region, you can do so on the Airola website do. It should be remembered that the eSIM is only suitable for data, not for regular calls. Unlike with a 2nd device, it is also not possible to make calls via WLAN-Call when used in a device. But usually it is sufficient to have a data connection, e.g. for Google Maps, while on vacation.
I will probably book an eSIM via this service at least during my next holiday, which will take me out of the EU and roaming. Certainly it may be a bit cheaper with matching regional SIMs, but the way via the eSIM functionality of modern iPhones is certainly much easier and you can choose the right provider before you start your journey.