The IRS allows you to claim investment expenses in excess of 2% of your adjusted gross income. Stock Rover would be considered such an expense.
The following are excerpts from IRS Publication 529.
You can deduct certain expenses as miscellaneous itemized deductions on Schedule A (Form 1040 or Form 1040NR). You can claim the amount of expenses that is more than 2% of your adjusted gross income. You figure your deduction on Schedule A by subtracting 2% of your adjusted gross income from the total amount of these expenses.
Qualified expenses include ordinary and necessary expenses paid in connection with books, supplies, equipment (including computer equipment, software, and service).