If I remember correctly, Niagara gives you fast text based app lookup as the primary means of accessing apps. Ulauncher offers the same interface as a fallback, but the primary means of accessing apps is via a small set of gestures on your homescreen.

From your comment I wanted to give Niagara a try, most useful features are apparently behind a pay wall, and that was completely fine... Until google asked me for my credit card details for the 7-days trial. This is probably none of Niagara's fault, but enough of a discouragement for me to give it a real chance.