Beat egg whites, cream of tartar or lemon juice and salt in a large bowl until soft peaks form. Gradually beat in sugar, one spoonful at a time, until mixture will hold stiff glossy peaks. Fold in almond extract. Line a baking sheet with parchment paper. Drop mixture from a spoon into 6 mounds; shape each into a circle, making the sides higher than the centre. Bake in a preheated 120°C (250°F) oven for 75 minutes or until dry and crisp. Turn oven off and cool in oven 1 hour with door slightly open.
To make citrus sauce:
Whisk yogourt, egg yolks, sugar and zest together in saucepan. Cook over low heat, stirring frequently until slightly thickened. Do not allow to boil. Remove from heat and pour into large bowl. Chill until serving time.
To garnish: Melt chocolate over low heat or in microwave oven on LOW. Drizzle chocolate over meringues. Fill with sauce and top with fruit.