The easiest solution would be to move the totals to the very first row in the sheet, like this:
- Choose View > Freeze > 1 row.
- Click cell A1 and choose Insert > Row above.
- Use cut (Control-X) and paste (Control+V) to move the summary formula cells from row 70 to row 1.
When the totals are at the top of the sheet, and the first row is in the frozen section, it will remain visible in the web version of Google Sheets as well as the Sheets iOS app.