Probably the most popular portfolio tracker out there only exists as a mobile app. It tracks a very large number of coins, and has a myriad of options, including checking the actual order book and on different exchanges for each coin, and a basic but usable news feed.
A particularly useful option are alerts when a coin reaches a certain price. Since many crypto exchanges don't fully support stop-loss orders, Blockfolio's alerts can be used for a quick profit cash-in or reducing your losses when the price starts dropping.
It's highly customizable: You can hide your balances and only see percentage changes, lock the app with a passcode, share screenshots, and more. It's also one of the visually nicest apps out there, with pretty charts and a choice between a night (dark) and day (white) UI mode.
Unfortunately, Blockfolio does sometimes stumble: It can be slow to list new coins, the prices it shows can be inaccurate, and its servers are sometimes unavailable.
If you want something similar to Blockfolio but a little faster and more reliable, Delta could be a good option for you. In my experience the prices on Delta were a little more accurate, and the app is very fast to list new coins.
Delta also has a few neat options such as a watchlist and the ability to track several separate portfolios.
However, when it comes to tracking individual coins, Delta does not have the versatility of Blockfolio; for example, you cannot look at a coin's actual order book on an exchange, only a chart of price changes over time, and there are no volume indicators on its charts.
Design-wise, Delta does not have the night mode option but the UI is predominantly dark and should work for most. If you, like I, are annoyed by waste of space in an app of this type, you can switch to a minimized layout under "Other Options" which will remove some necessary blank space in the app's default view.
Unlike Delta and Blockfolio, Cryptopanic is not a mobile app at all — it's a web page, but it works flawlessly on both desktop and mobile. It also has a dual function; it's a news aggregator with social functions such as voting, and a portfolio tracker.
The portfolio tracking part of Cryptopanic is working amazingly well: You search for a coin, enter the amount you own, and it's added to your portfolio. You cannot track prices on individual exchanges, but Cryptopanic is doing a solid job at tracking prices, and it also has an "extended" view mode which shows you the price of coins in several currencies: USD, ETH and BTC (tracking the price in ETH is a feature that's sorely lacking in most portfolio trackers).
Arguably, the best part of Cryptopanic is not the portfolio tracker but the News portion of the app. It offers an extremely good overview of the latest crypto-news, with the ability to filter by coin and relevance.
My favorite feature of Cryptopanic, however, is its minimalist, retro-look which makes the app a joy to look at on both mobile and desktop.
Cryptopanic is available at cryptopanic.com . It's free but it has a Pro mode that lets you add custom news sources and disable existing news sources for $9 per month or $99 per year.