You can still buy bal flex....
BAL Flex Powder & Liquid
A two part, water-resistant and frost-resistant wall tile adhesive, suitable for use in interior and exterior locations. Suitable for fixing ceramic wall tiles and mosaics and dark natural stone. Suitable for use on concrete/brick/block walling, cement:sand rendering, plaster, plasterboard, plywood/chipboard, tile backer boards, glazed tiles/bricks, painted walls, glass reinforced polyester (GRP) backgrounds, steel and galvanised steel. Conforms to BS EN 12004, Type C, Class 1T.
BAL Fastflex Powder & Liquid
A two part, rapid-setting, sulphate-resistant, water-resistant and frost-resistant floor tile adhesive and isolating, anti-fracture underlay, suitable for use in interior and exterior locations. Suitable for fixing ceramic floor and porcelain tiles and mosaics (including fully vitrified), dark natural stone and slate. Suitable for use on tile backer boards, glazed tiles, concrete bases, cement:sand screeds, tongue & groove floorboarding, plywood overlay, floating plywood/chipboard floors, ceramic/quarry tile/terrazzo/hard natural stone bases, vinyl tiles/sheet, mastic asphalt, steel, glass reinforced polyester (GRP), steel and galvanised steel. Conforms to BS EN 12004, Type C, Class 1F.