Barcode Studio is the free barcode generation solution for mostly all known barcodes. Currently the app is able to encode data in over 40 barcode symbologies.
The app is free (ad supported). Encoding happens on the smartphone without the help of a web service, so you can create barcodes without being connected to the Internet.

There is an in-app purchase to remove ads and enable the favorites and history features. The 'favorites' feature allows you to save your frequently used barcodes while the 'history' feature provides access to the latest genererated barcodes.
The in-app purchase is not necessary to create barcodes but it adds convenient features for regular users.

Currently the following symbologies are supported:
Code 11, Code 2 of 5 (interleaved), IATA, Data Logic, Industrial, Code 39 (extended), EAN, GS1-128, Codabar, Code 32, Code 49, Code 93, Code 128, Deutshe Post Leitcode, Deutsche Post Identcode, Code 16K, DataBar (14, limited, extended),
Telepen (alpha/numeric), UPC A/B, PostNet, MSI Plessey, LOGMARS, Pharmacode One-Track/Two-Track, PDF417 (truncated), Maxicode, QR Code (standard and micro), Australian Post Codes, ISBN, Royal Mail, Data Matrix, NVE-18, Japanese Postal Code, Korea Post,
GS1 DataBar-14 (stacked, omnidirectional, expanded stacked), PLANET, PDF417 (standard and micro), USPS OneCode, Plessey Code, ITF-14, Dutch Post KIX Code, Aztec Code (standard and runes).
HIBC is supported in all symbologies where a HIBC specification is available.