Solar eclipses are relatively uncommon phenomena. TPE for iOS includes a list of such events (currently for the period through to 2021). You can view the event list by tapping the date at the top of the screen:
As the time of totality for the eclipse varies by location, you can research the precise time for your shot plan using the external links provided in the event details:
Alternatively, you can adjust the time slider below the map to view when the azimuth and altitude of both sun and moon are equal:
However, given the brevity of totality and the importance of getting the timing exactly right, we encourage users planning an eclipse shot to use other resources to determine exact timings for their location, in conjunction with TPE to evaluate the position of the sun and moon relative to the landscape.
The NASA Eclipse Site is highly recommended: