Pana, a travel companion that organizes your plans and sends personalized trip alerts, is now making its app free to challenge rivals like TripIt, Google Trips and others. First launched two years ago, Pana had previously focused on its paid subscription service for individuals and companies needing a 24/7 travel concierge — a move that may have limited its potential market. The free app (ver. 3.0), launched this week, brings a wide set of Pana’s features to those who may not be frequent fliers in need of Pana’s more hands-on service.