As of now, it is challenging to provide an exact ranking of cryptocurrency app downloads in Islamabad, Pakistan since this data is not publicly available. However, based on general trends and usage patterns, we can make an educated guess on the popularity of certain cryptocurrency apps in the region.

1. Coinbase: Coinbase is one of the most popular cryptocurrency apps globally, offering a user-friendly interface and a wide range of cryptocurrencies for trading.

2. Binance: Binance is another popular cryptocurrency exchange that offers a diverse selection of cryptocurrencies and advanced trading features.

3. eToro: eToro is known for its social trading platform, where users can follow and copy the trades of successful cryptocurrency traders.

4. Kraken: Kraken is a well-established cryptocurrency exchange with a strong reputation for security and reliability.

5. Trust Wallet: Trust Wallet is a mobile wallet app that allows users to store a wide range of cryptocurrencies securely on their mobile devices.

6. Coinomi: Coinomi is a popular multi-currency wallet app that supports a wide range of cryptocurrencies and tokens.

7. BitPay: BitPay is a popular payment app that allows users to store and spend cryptocurrencies at various merchants and online stores.

8. Blockfolio: Blockfolio is a popular cryptocurrency portfolio tracking app that allows users to monitor their investment performance in real-time.

9. Crypto.com: Crypto.com is a cryptocurrency platform that offers a range of products and services, including a mobile wallet app and a crypto debit card.

10. Exodus: Exodus is a desktop and mobile wallet app that supports a wide range of cryptocurrencies and offers a simple and intuitive user interface.

These are just a few examples of popular cryptocurrency apps that are likely to have a significant number of downloads in Islamabad, Pakistan. It's important to note that the popularity of these apps can vary over time, so it's always a good idea to do your research and choose the app that best meets your needs and preferences.