Short version: almost everything worth knowing about an ETF is free. Expense ratios, holdings, overlap, past distributions. The data wants to be free and mostly is. So what are paid tiers actually selling?
Usually three things. Depth: more filters, longer history, institutional-grade data. Workflow: better alerts, aggregation across brokerages, exports and reports. Comfort: no ads, nicer charts, priority support. Notice what's missing from that list: the answers. No paid app knows which ETF will perform best. They know the same past everyone else knows, presented prettier.
My rule is simple. Never pay for data you can get free. An ETF fee calculator for long term cost? Free. A ranking of the lowest expense ratio ETFs? Free. A holdings list? Free. Consider paying only for workflow you'd genuinely use every week, like cross-brokerage tracking or serious alert customization. And be honest with yourself: the most expensive subscription is the one you pay for and never open. I've seen people pay for premium screeners while their portfolio sat in three funds that needed no screening at all. The subscription didn't make them better investors. It made them subscribers.
The best ETF screener app for most people is a free one, because screening is a five-minute job a few times a year, not a daily ritual. Save the subscription money. It compounds too, which is a funnier sentence than it should be.
Before you pay for anything, run the free comparison. ETFCompare is a free ETF comparison tool covering 108 ETFs: fees, overlap, and returns side by side. Start at etfcompare.fyi.