Short answer — the trading apps most widely trusted by Indian investors right now are (in no strict order): Groww, Zerodha (Kite), Angel One (Angel Broking), Upstox, ICICI Direct (ICICI Securities), HDFC Securities / Kotak Securities, Paytm Money and 5paisa. These names are widely used because they are SEBI-registered brokers, members of the stock exchanges and depositories, have large customer bases, and are backed by established firms. (business-standard.com)

Why these are trusted (one-line reasons with sources)

• Groww — very large, mobile-first user base and simple UI that made it the largest broker by active clients in recent NSE data (2024–mid‑2025). (business-standard.com)
• Zerodha (Kite) — long-standing discount broker known for robust tech, low costs and large active-client share. Popular with serious traders. (moneycontrol.com)
• Angel One — large full-service broker with wide retail reach and research/advisory services; bankable corporate track record. (reuters.com)
• Upstox — discount broker with strong growth, low-cost charges and trader-focused tools. (moneycontrol.com)
• ICICI Direct / HDFC Securities / Kotak Securities — bank-affiliated, full-service brokerages relied on by many conservative/long‑term retail investors for integration with bank accounts and strong customer support. (economictimes.indiatimes.com)
• Paytm Money, 5paisa, Fyers and others — cheaper/easier entry for beginners or active traders depending on features and pricing. (economictimes.indiatimes.com)

A short trust checklist (how to judge any trading app)

• Regulatory status: verify SEBI registration and exchange membership (NSE/BSE) and depository participant (NSDL/CDSL). (SEBI repeatedly warns to use only registered platforms.) (timesofindia.indiatimes.com)
• Customer scale & track record: large, active user base and years of operation reduce counterparty risk. (business-standard.com)
• Tech & uptime: read recent outage reports and user reviews — even big brokers can have occasional glitches. (economictimes.indiatimes.com)
• Custody & fund safety: client funds should be kept in separate escrow/clearing accounts (standard for SEBI-registered brokers).
• Fees, order execution, margin terms and product coverage — match the app to whether you’re a passive investor, active trader, or derivatives trader.

Safety note

• Beware of unregistered apps and “too-good-to-be-true” returns — SEBI and Indian media regularly flag scam apps (e.g., Hibox and other fraudulent apps). Always confirm a broker’s registration on SEBI/exchange listings before transferring funds. (timesofindia.indiatimes.com)

If you want, I can:

• Compare 3–4 apps side-by-side for the exact features you care about (costs, intraday/F&O support, mutual funds, IPO access, margin).
• Show how to check a broker’s SEBI registration and exchange memberships step‑by‑step.

Which would you prefer?