WhatsApp SIM is a free iPhone app developed by Telefonica Germany GmbH & Co. OHG. This app provides users with a convenient way to check their usage, top up their balance, and book tariff options.

With WhatsApp SIM, you can easily manage your account and stay on top of your mobile usage. The app allows you to check your balance, ensuring that you always know how much credit you have remaining. Additionally, you can book and cancel tariff options to suit your needs, giving you the flexibility to choose the right plan for you.

One of the key features of WhatsApp SIM is the ability to check your available units. Whether it's minutes, texts, or data, you can easily keep track of how much you have left. This ensures that you never run out of credit or exceed your usage limits.

Furthermore, the app allows you to manage your customer data, providing a convenient way to update your information whenever necessary. Whether it's changing your address or updating your payment details, WhatsApp SIM makes it easy to keep your account up to date.

Overall, WhatsApp SIM is a user-friendly app that offers a range of features to help you manage your mobile account and tariffs with ease. Whether you're a new or existing WhatsApp SIM user, this app is a valuable tool for staying in control of your mobile usage.