I've got a financial tracking app that can keep track of my net worth. I can add a bitcoin address and it will keep track of my BTC, and include it in the total.
If you want to, you can probably manually enter the amount of your cryptocurrency holdings (like BTC) in some applications to achieve the same effect as using an automatic API or integration. The specific application you're using will determine whether or not this is possible, but it's definitely worth exploring as an option.
Do I have any reason to be concerned about giving this app my bitcoin address? Will it only be able to view my wallet total/transactions?
When it comes to the security of your crypto assets, you don't need to worry. However, when it comes to privacy, it's important to be aware that there are some potential risks to consider.
Should I create a new address for this purpose?
I use bitcoin core
It's entirely up to you and your personal preferences. As I mentioned previously, one option to consider is manually entering your amounts without providing too much of your personal information to the app.